I recently switched over from At&T to T-Mobile. Today I didn't receive any texts or phone calls and missed some important calls at work. When I was walking to my car, I started getting all these text messages and voicemails. I got home and restarted the phone to see if that would fix it, and then I got a text message saying service is unavailable. I went to a T-Mobile store and they tried messing with the settings. I did a factory restart and still nothing. The only thing I can think of is I got a faulty refurbished phone from At&T or I got blacklisted for some reason

Hmm, that's really weird. As long as the APN settings are correct, it should work. It's not something we can guarantee, but more often than not, it works on unlocked. Do you have a T-Mobile phone you could test your SIM in for a moment just to make sure this issue isn't following to another phone?

I tried the sim card to another phone, tmobile phone, it works just fine.

What is it with ATT unlocked phone that creates this. 2 days ago just fine, but suddenly the 3rd day after porting it stopped working. What did ATT do? do you know if you could help us who already paid our phone in full, ported over and but STUCK? @tmo_marissa @tmo_mike_c

Aw man, sorry this happened to you too combiblock. I'm sure AT&T hasn't done anything. The tricky thing about unlocked devices is that it can be hit or miss when it comes to working on our network. As long as the device is unlocked and our settings are entered correctly, in theory, it should work. Experience has taught me that's not always the case. Which is why we have our disclaimer for folks wanting to bring their own devices.

I remember back in the days when this happened on iPhones from AT&T. It was a mystery because they would stop connecting to data all of a sudden and there was no change in the software or the settings. It was weird because the service just seemed to stop with no real reason why. It didn't happen on every single phone, but I came across folks that experienced this. I had to let them know the same thing about the service being hit or miss.

I know that altering that setting every time you restart isn't the most convenient thing, but I'm glad that you have a workaround you can use sandokpn! Thank you for the update - maybe it will prove useful to another user on this thread!

I reset and rebuilt the APN (many times) and did everything short of rooting (much of this with support of T-Mobile telephone and message resources, and also reliable forums I have come to reliy on over the years), but in the end it still had these major problems:

- No phone call ability much of the time in AT&T roaming.

- Mostly AT&T roaming, and never connecting to Band 12 towers

- Call/text ability frequently dying, and only coming back from also frequent Airplane Mode On/Off

and I consider that question answered. I eventually gave up on the idea of the former AT&T unlocked S7 Active being an effective T-Mobile phone to reliably function and fully make use of the available T-Mobile network and features. I hope you find this discussion relevant to your experiences.

Thank you for all the advice and comments. Sorry for the delay, but i don't know what i did besides putting in the APN settings manually. It took a couple days of just messing with the settings but it just worked. Now everything has been working fine since I posted my original question. I haven't restarted my phone to see if it still works since everything starting working. (knock on wood) but i hope everyone can get theirs to work

Like the others, I brought my S7 Edge to t_mobile from AT&T. After porting, all was great for about 2 days. Now, no internet, no email.

Support states 3 days to "research" the problem. I visited 2 stores, but no answers after resets, changing APN, calling support themselves.

What is the fix for the problem? Looking on line, I see several threads about the issue, but no resolution. One would think someone with T-Mobile knows the answer. One person in the store suggested I purchase a T-Mobile ready phone. Is there a fix for this?

littleb411 After changing APN settings, etc. it worked great until the phone was rebooted. But then to test another users forum thread on this site, we simply enabled Airplane Mode, waited a few seconds, then disabled Airplane Mode. Walla, data started working again!

We've had to use this little trick several times after rebooting the phone or when data stops working, and it someone gets it working again. I can't find the thread at the moment, but if I do I will update this comment.

I've just moved last night from AT&T with my AT&T branded unlocked S7 (that i bought from Target) and I have run into the same problem as the OP this afternoon. Using the airplane mode tip from gunn317, I now have 4G LTE back!!! It's not a permanent solution I don't think but it'll do for now.

I'm going to continue looking to see if something permanent crops up.

FYI: I also got the info from a T-Mobile tech that they feel it may be an issue with the phone coming over from AT&T.

I have the exact same problem. Tech support told me it was "betterment" work in the area I was in, but as soon as I turned on airplane mode and back off it started working immediately. Maybe the engineers can come up with a permanent solution since it seems like this is happening alot.

Call tmobile and tell them to activate your wifi calling. Your wifi calling is not active. Thats how i fixed the wifi calling feature on my brand new at&t unlocked galaxy note 5 but the 4g lte is not stable like it is on my tmobile galaxy s8. I do not know how to fix that issue. Every store rep has not been able to fix that issue. The 4g lte works maybe for 30 minutes then switches to ege, and It stays on edge without reverting back to lte.